DOCSLIB.ORG

Defoamers and Their Use

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Defoamers and Their Use Europaisches Patentamt J European Patent Office 00 Publication number: 0 345 042 Office europeen des brevets A2 EUROPEAN PATENT APPLICATION Application number: 89305485.8 S) IntCI.4: B 01 D 19/04 Date of filing: 31.05.89 ® Priority: 02.06.88 GB 8813018 (72) Inventor: Reed, Kenneth Gordon Steenweg OP Leuven 65 @ Date of publication of application : B-1980Tervuren (BE) 06.12.89 Bulletin 89/49 Godwin, Allen David Avenue de I'Orangerie 9 @ Designated Contracting States : B-1410 Waterloo (BE) AT BE CH DE ES FR GB GR IT LI LU NL SE Geiregat, Nancy Madeleine Michele © Applicant: EXXON CHEMICAL PATENTS INC. Kappellestraat110B1 200 Park Avenue B-9800Deinze (BE) Florham Park New 07932 Jersey (US) Hentges, Steven George 1012 Stoneleigh Drive Baton Rouge Louisiana 70808 (US) @ Representative: Bawden, Peter Charles et al EXXON CHEMICAL LIMITED EXXON CHEMICAL TECHNOLOGY CENTRE PO Box 1 Abingdon Oxfordshire OX13 6BB (GB) (§4) Defoamers and their use. (g) Finely divided polyethylene waxes having terminal acetyl groups are effective defoamers which may be used both for defoaming and antifoaming. For this purpose they are formu- lated as liquid compositions comprising a suspension of the wax in an organic liquid containing appropriate surfactants and may be used as emulsions or solutions in hydrocarbon solvents. CM 3 in CO Q. LU Bundesdruckerei Berlin EP 0 345 042 A2 Description DEFOAMERS AND THEIR USE This invention relates to defoamers and to their production and use. Defoamers are used in a wide variety of industries. They function both as antifoamers, to prevent build-up of 5 foam, and as defoamers to destroy foams which have already formed. They are also used as de-aerating agents to accelerate the escape of entrapped air. The term "defoamer" is used to cover materials which have either antifoaming or defoaming efficiency or both. When used in "antifoaming", i.e. to prevent foam formation, the defoamer is added to the liquid which is liable to foam before any foam formation takes place. The efficiency of a defoamer in this context is measured by its effectiveness in preventing or minimising foam 10 formation. The term "defoaming" refers to the ability of a defoamer which shows good antifoaming activity may be expected to show also good defoaming activity, this is by no means always the case, and a defoamer may be a good antifoaming agent or a good defoaming agent without also being respectively a good defoaming agent or a good antifoaming agent. Known defoamers may be supplied as solutions, suspensions, emulsions or as solids. The most effective 15 and widely-used defoamers are however suspensions of finely-divided solid particles dispersed in an organic, often hydrocarbon, medium although there is a trend to use emulsion based products to avoid the environmental problems associated with the use of the hydrocarbon medium. Defoamers based on suspensions of finely-divided ethylene bis-stearmide particles in an organic medium are very widely used in paper-pulp processing, and paper manufacture. Such defoamers generally consist of a 20 suspension of finely-divided ethylene bis-stearmide particles in a hydrocarbon medium which has dissolved therein one or more surfactants which act as emulsifying and spreading agents. These compositions are effective in a wide variety of circumstances, but ethylene bis-stearmide is an expensive material and there is a need for cheaper defoamers. Indeed, in some cases it is preferable to use a relatively large quantity of a cheap, relatively inactive defoamer rather than a small quantity of an expensive but highly active defoamer, even 25 though the overall cost may be approximately the same, because in many instances it is easier to control the use of relatively large amounts of defoamer rather than small amounts which must be accurately measured. The present invention is based on the discovery that polyethylene waxes having terminal acetyl groups are very effective defoamers. When correctly formulated, they are in many contexts as effective as ethylene bis-stearamide, with the important advantage that they are much cheaper; they may also be used in emulsion 30 based defoamer systems. The use of these waxes enables emulsion defoamers in which the wax is the only active defoamer component unlike previous wax based emulsion defoamers which generally contain additional active defoamer material. The present invention accordingly provides a method for suppressing or preventing foam which comprises adding to a foamed or foamable liquid an effective amount of a finely-divided polyethylene wax having terminal 35 -COCH3 groups and containing 50-400 carbon atoms per molecule. Such polyethylene waxes are normally supplied and used in the form of a liquid defoamer composition comprising a suspension of the finely-divided solid polyethylene wax in an organic liquid carrier, e.g. a petroleum or other hydrocarbon oil or a fluid synthesised by the oxo-process, which has dissolved therein one or more surfactants effective as emulsifying and spreading agents. 40 The solid polyethylene waxes used in the present invention are known materials which are described for example in United States Patent No. 4698450. They are made by the polymerisation of ethylene in the presence of acetaldehyde as chain transfer agent in the way described in the said patent. A variety of grades of such waxes are commercially available having molecular weights ranging from about 800 to about 5,000, and a blend of such waxes may also be used. The defoamer compositions of the present invention usually contain 1 to 15<Vo 45 by weight of the wax. The carrier used in the new defoaming compositions may be a hydrocarbon carrier similar to those used in known defoaming compositions. This may be, for example, a light mineral oil, or a so-called spindle oil. Suitable mineral oils may have a viscosity of about 20 cSt at 40° C. Preferably, however, the carrier used in the present invention is an organic fluid obtained by the oxo-process, and more particularly a mixture of higher (i.e. C16 to 50 C22) aliphatic ethers and ether-alcohols, usually associated with a small proportion of corresponding alcohols of mainly 8 to 11 carbons such as isodecanol, and a small proportion of less volatile compounds. Such materials are commercially available, e.g. the product known as MD-OC-H supplied by Exxon Chemicals. This product consists mainly (over 80%) of aliphatic ethers and ether-alcohols in which the carbon chains contain 20 to 22 carbon atoms. A small proportion (less than 10%) of alcohols containing 9 to 1 1 carbon atoms is also 55 present. It has been found that these materials are superior to hydrocarbons as carriers in the defoamer compositions of the present invention. The combination of the defoamer and the oxo-process oil is particularly desireable when the defoamer is used as an emulsion since the emulsion has low viscosity and may be more readily used than other water-based defoamers. The surfactants used in the new compositions may be similar to those used in known defoamers, and 60 especially anionic surfactants, non-ionic surfactants or a mixture of both. Suitable anionic surfactants include the sulphonates of aromatic hydrocarbons and the sulphates of long chain aliphatic alcohols which may be polyoxyethylenated. Suitable non-ionic surfactants include polyoxyethylenated long chain aliphatic esters of polyethylene glycols of high molecular weight, e.g. 200 to 800. EP 0 345 042 A2 The new defoamer compositions are conveniently made by mixing the specified ingredients. Preferably, the ketonic polyethylene is dissolved in the carrier at elevated temperature and the homogeneous mixture is then quickly cooled, e.g. to 0° C. This causes the ketonic polyethylene to precipitate out in the form of solid particles of the required particle size. Such compositions have, however, sometimes an inadequate shelf-life for some purposes. Shelf-life can be substantially improved, and the defoaming activity often increased, by homogenising the mixture. The usual industrial equipment may be used for this purpose, e.g. a Gaulin homogeniser, using a pressure of, e.g., 500 bars. During the homogenisation, the temperature of the mixtures typically reaches about 35° C. The surfactants are preferably dissolved in the carrier before the ketonic polyethylene is added, but may, if desired, be added later. 10 The new defoamer composition may contain, in addition to the ingredients already mentioned, a small proportion of other constituents as used in known defoamers, e.g. finely-divided hydrophobised silica and/or a silicone oil. Such additives tend however to increase the overall cost of the defoamer composition and are not therefore desirable where cost is a prime consideration, e.g. in large-scale uses. Although the preferred compositions in accordance with the invention consist of the ketonic polyethylene 15 dispersed in an organic carrier, it is possible to make an oil-in-water or water-in-oil emulsion defoamer in which the finely-divided ketonic polyethylene and the organic carrier are dispersed in water or water is dispersed in the organic carrier. Oil-in-water emulsions can be advantageous where the defoamer is to be substantially diluted before use since for environmental and cost reasons water is the preferred diluent. The ketonic polymer may be the only particulate defoamer in those systems which are efficient, stable, of long life and low 20 viscosity. In the following examples, the particulate active defoamer may be any one of the following ketonic polyethylene waxes: 25 ECEA-1 ECEA-2 ECEA-3 ECEA-4 Molecular weight 800 4850 1100 1100 30 Carbon chain length 52 350 78 78 Density (g/ml) 0.948 0-950 0.950 35 Vicat softening point ) 102 65 68 ASTM D1525 (*C) ) 40 Ring & ball softening ) 119 115 112 point, ASTM E 28 (°C) ) 45 Viscosity at 121 °C, ASTM D 3236 ) 1200 27 27 50 (mPa.S) ) * ECEA-1 is a paste at room temperature 55 ECEA-3 is similar to ECEA-4 but is manufactured to higher specifications than ECEA-4 and therefore gives greater reproducibility of results.
Load more

Recommended publications
  • Defoamer Formulation Entschäumerzusammensetzung Composition Antimousse
    (19) TZZ ¥ZZ_T (11) EP 2 430 095 B1 (12) EUROPEAN PATENT SPECIFICATION (45) Date of publication and mention (51) Int Cl.: of the grant of the patent: C08L 33/06 (2006.01) B01D 19/04 (2006.01) 07.03.2018 Bulletin 2018/10 (86) International application number: (21) Application number: 10720061.0 PCT/US2010/033827 (22) Date of filing: 06.05.2010 (87) International publication number: WO 2010/132262 (18.11.2010 Gazette 2010/46) (54) DEFOAMER FORMULATION ENTSCHÄUMERZUSAMMENSETZUNG COMPOSITION ANTIMOUSSE (84) Designated Contracting States: • WILSON, Robert AL AT BE BG CH CY CZ DE DK EE ES FI FR GB Marietta, GA 30060 (US) GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO • ROSENCRANCE, Scott PL PT RO SE SI SK SM TR Douglasville, GA 30135 (US) • PREVIS, David (30) Priority: 15.05.2009 US 466637 King William, VA 23086 (US) (43) Date of publication of application: (74) Representative: Potter Clarkson LLP 21.03.2012 Bulletin 2012/12 The Belgrave Centre Talbot Street (73) Proprietor: Kemira Chemicals Inc. Nottingham NG1 5GG (GB) Atlanta GA 30339 (US) (56) References cited: (72) Inventors: GB-A- 2 094 330 US-A- 5 152 925 • MARTIN, James Bonaire, GA 31005 (US) Note: Within nine months of the publication of the mention of the grant of the European patent in the European Patent Bulletin, any person may give notice to the European Patent Office of opposition to that patent, in accordance with the Implementing Regulations. Notice of opposition shall not be deemed to have been filed until the opposition fee has been paid.
    [Show full text]
  • The Activated Sludge Process Part 1 Revised July 2014
    Wastewater Treatment Plant Operator Certification Training Module 15: The Activated Sludge Process Part 1 Revised July 2014 This course includes content developed by the Pennsylvania Department of Environmental Protection (Pa. DEP) in cooperation with the following contractors, subcontractors, or grantees: The Pennsylvania State Association of Township Supervisors (PSATS) Gannett Fleming, Inc. Dering Consulting Group Penn State Harrisburg Environmental Training Center MODULE 15: THE ACTIVATED SLUDGE PROCESS - PART 1 Topical Outline Unit 1 – General Description of the Activated Sludge Process I. Definitions A. Activated Sludge B. Activated Sludge Process II. The Activated Sludge Process Description A. Organisms B. Secondary Clarification C. Activated Sludge Process Control III. Activated Sludge Plants A. Types of Plants B. Factors that Upset Plant Operation IV. Unit Review V. References Unit 2 – Aeration I. Purpose of Aeration II. Aeration Methods A. Mechanical B. Diffused III. Aeration Systems A. Mechanical Aeration Systems B. Diffused Aeration Systems Bureau of Safe Drinking Water, Department of Environmental Protection Wastewater Treatment Plant Operator Training i MODULE 15: THE ACTIVATED SLUDGE PROCESS - PART 1 IV. Safety Procedures A. Aeration Tanks and Clarifiers B. Surface Aerators C. Air Filters D. Blowers E. Air Distribution System F. Air Headers and Diffusers V. Review VI. References Unit 3 – New Plant Start-Up Procedures I. Purpose of Plant and Equipment Review A. Document Familiarization B. Equipment Familiarization II. Equipment and Structures Check A. Flow Control Gates and Valves B. Piping and Channels C. Weirs D. Froth Control System E. Air System F. Secondary Clarifier III. Process Start-Up A. Process Units B. Process Control IV. Unit Review V.
    [Show full text]
  • Labels of Pesticides Used with This Product
    Brandt® Organics Defoamer Antifoaming / Defoaming Agent KEEP OUT OF REACH OF CHILDREN Principal Functioning Agents: Silica filled polydimethylsiloxane .................10% WARNING Constituents ineffective as spray adjuvant ....... 90% Total........................................... 100% PRECAUTIONARY STATEMENTS CA Reg. No. 48813-50022-AA HAZARDS TO HUMANS AND DOMESTIC ANIMALS DIRECTIONS FOR USE WARNING: Causes serious eye irritation. Causes skin irritation. Wear protective eyewear, long sleeved shirt, long pants, shoes BRANDT ORGANICS DEFOAMER is a high quality silicone based plus socks and chemical resistant gloves made of any waterproof anti-foaming agent designed to prevent foam formation or defeat material when mixing or handling concentrate. Wash thoroughly existing foams in pesticide spray solutions. Excessive foaming with soap and water after handling and before eating, drinking, can promote inefficiency in spray activities. It may be used on chewing gum, using tobacco, or using the toilet. Remove and wash agricultural, forestry, turf and ornamental, industrial, structural contaminated clothing before reuse. and non-cropland sites. Not for aquatic use. Read and follow the precautions, restrictions and recommendations ENVIRONMENTAL HAZARDS on the labels of pesticides used with this product. Use according to Do not contaminate water when cleaning equipment or disposing the most restrictive label directions for each product in any tank mix. of equipment washwaters. COMPATIBILITY: BRANDT ORGANICS DEFOAMER is compatible FIRST AID with most pesticides. However, if the desired combination has Have the product container or label with you when calling a poison not been previously used, a compatibility test is recommended. control center or doctor or going for treatment. MIXING: Fill spray tank 1/2 full of water and begin agitation.
    [Show full text]
  • Glossary: Wastewater Treatment and Collection System Terms
    Glossary September 2011 Wastewater Treatment Collection System &Terms Minnesota Pollution Control Agency 520 Lafayette Road North St. Paul, Minnesota 55155-4194 wq-wwtp8-20 Contents Wastewater Treatment and Collection System Terms A ........... 3-6 G ...... 24-25 M ..... 29-31 S ........ 42-51 B ........... 7-9 H ....... 26-27 N ....... 32-33 T ........ 52-54 C ....... 10-15 I ......... 27-28 O ...... 33-35 U ............ 54 D ....... 15-19 J ............. 28 P ....... 35-40 V ....... 55-56 E ........ 19-21 K ............ 28 Q ............ 40 W ...... 56-57 F ........ 21-24 L ............. 29 R ....... 40-42 Z ............. 57 Acknowledgement Special thanks to Ken Kerri at California State University, Sacramento, for use of the glossary that appears in his self-study training courses, “Operation and Maintenance of Wastewater Collection Systems” and “Operation of Wastewater Treatment Plants.” A special acknowledgement to the Water Environment Federation for the use of their wastewater glossary for some of the definitions in this manual. Contributors Kay Curtin Steve Duerre Gene Erickson Editing and Graphic Design Nancy Ellefson This document was printed on 30 percent post-consumer recycled paper manufactured without the use of elemental chlorine. 2 Minnesota Pollution Control Agency | All rights reserved. Wastewater Treatment and Collection System Terms A absorption The taking up of one substance into the body of another by chemical or molecular action after the adsorbtion process. accuracy In physical measurements, it is the degree of agreement between the quantity measured and the actual quantity. It should not be confused with ‘precision,’ which denotes the reproducibility of the measurement. acid A substance that yields hydrogen ions when dissolved in water resulting in a pH of less than 7; it can react with bases and certain metals to form salts.
    [Show full text]
  • Predicting Defoamer Performance in Coating Formulations
    Predicting Defoamer Performance in Coating Formulations C. James Reader and K.T. Griffin Lai Air Products and Chemicals, Inc., 7201 Hamilton Boulevard, Allentown, PA 18195-1501 C. James Reader, [email protected], 610-481-7380 K.T. Griffin Lai, [email protected], 610-481-7069 Introduction What is the usual procedure for finding a defoamer for a new waterborne coating formulation? For many companies, the procedure appears to be as follows: try the defoamers that you currently use and know; if these don’t work then try samples in the lab, ask a colleague or friend or, maybe, ask a supplier. This approach makes good sense when working with formulations that are similar, as defoamers will usually give consistent performance in similar formulations. However, when these tried and trusted defoamers don’t work, the Chemist has the frustrating task of trying to find a suitable product from a large selection of mysterious bottles on his or her lab bench. There is a truism in England that goes “if all else fails, read the instructions”; however, defoamers don’t usually come with instructions. Wouldn’t it be nice if they did? The difficulties in finding a suitable defoamer exist because the performance of each and every defoamer is affected by the formulation it is used in; change the formulation and the defoamer performance may often change as well. Defoamer selection is also one of the last steps in readying a formulation for final use, so the rest of the formulation is already mostly decided and the defoamer has to work with this.
    [Show full text]
  • Industrial Fluids
    INDUSTRIAL FLUIDS ADDITIVES For more than 180 years, MÜNZING has been Defoamer Technology helping its customers perfect their products by What is Foam? 1 creating specialty additives that are precisely right for them. Headquartered in Abstatt, Germany, Product Offerings our manufacturing plants in North America and Germany have broad synthesis and formulation Metalworking 2 capabilities to best serve our global customer base. Tankside Defoamers 3 MÜNZING has a presence in more than 40 countries Industrial Cleaners 4 and is a technology-driven organization with an extensive network of highly skilled R&D and Antifreeze, Engine Coolants and De-Icing 5 technical service professionals. Our additives have achieved worldwide recognition for their Non-Aqueous Lubricants 6 performance, quality and technical innovation. Energy – Oil Field 7 This first-class product line includes defoamers, dispersants, rheology modifiers, emulsifiers, Surface Finishing 8 wetting and leveling agents, micronized and coated waxes, and wax dispersions and emulsions. Test Methods of IFL Applications 9 If you have a specific challenge, we have the Evaluation of Compatibility 9 technical expertise and laboratory capabilities Foam Tests: Aqueous Applications 10 to craft a unique solution. As a highly regarded, privately owned company, MÜNZING is committed Foam Tests: Non-Aqueous Applications 11 to providing an unmatched level of technical service to all of our customers and to ensuring Additive Products, Theory and Application that our products deliver optimal performance.
    [Show full text]
  • Z-90 Defoamer -Food Grade Defoamer
    Z-90 Defoamer -Food Grade Defoamer- Technical Information Product Description Z-90 Defoamer food-grade antifoaming agent is a water-based silicone emulsion designed to control foam in aqueous food processing applications. The functional properties developed especially for these antifoams is to eliminate and prevent excessive foam, which include: quick dispersibility, slight insolubility, relative stability, and a high degree of spreadability in the foaming system. The primary active ingredient, polydimethyl siloxane, is an FDA-approved liquid silicone polymer. It is USDA approved to be used in cleaning solutions and also as a direct additive to food products. Z-90 Defoamer functions both as an antifoam (prevents foam formation) and as a defoamer (collapses foam formation). Z-90 Defoamer utilizes only food-grade, nonionic emulsifiers; and contains only ingredients that are recognized by qualified experts as safe in food products according to the Code of Federal Regulations, Title 21, Part 173.340. It may therefore be used as direct food additives in most foods. As a processing aid, Z-90 Defoamer is considered a "secondary direct food additive" and imparts no flavor, odor, or functional attributes to the food. Anderson Chemical Company certifies that this product is acceptable for use as a general cleaning agent on all surfaces, or for use with steam or mechanical cleaning devices in all departments and as a foam control compound (former USDA A1, Q5 authorization). Properties Form.................................................................................. White viscous liquid Specific Gravity,Density.................................................. 1.00@68°F, 8.33 lb./gal. Viscosity........................................................................... 1,000-4,000 cP @20 rpm pH, (Neat - as is)............................................................... 7.5-8.25 Foaming Tendency.........................................................
    [Show full text]
  • Oil Production in Libya Using an ISO 14001 Environmental Management System
    Oil production in Libya using an ISO 14001 environmental management system To the Faculty of Geosciences, Geo-Engineering and Mining (3) Of the Technische Universität Bergakaemie Freiberg is submitted this THESIS To attain the academic degree of Doktor ingenieur (Dr.-ing.) submitted by BSc. petroleum engineer MSc. petroleum engineer Biltayib. M. Biltayib born on 17 February in 1974, Sirte, Libya Freiberg, 06. 01. 2006. Date of submission Dedication To my father and mother who supported me and lighted up my life since my birth to this date. To my brothers and sisters for their effort, moral support and endless encouragement. Biltayib. M. Biltayib 2 Acknowledgements First of all I wish to express my sincere thanks and gratitude to my supervisor Prof. Dr. Jan C. Bongaerts for their friendly assistance, guidance, discussion and criticism that made study interesting and successful. I am grateful to the staff of IMRE, TU Bergakademic Freiberg, Dipl.-Ing. Stefan Dirlich, Kristin Müller, who gave useful contributions at various times during the development of this thesis. I appreciate the support of the staff of AGOCO , Dipl.-Ing. Soliman Daihoum, Mr. Hassan Omar, Dipl.-Ing Ibrahim Masud during the data collection. Finally thanks to my special friends, Dr. Mohamed Abdel Elgalel, khalid kheiralla, Khaled raed, Dr. Aman Eiad , Dr. Saad Hamed, Mahmud Guader, Samuel Famiyeh, Abdallminam, Salem kadur, Abdalgader Kadau , Mohammed Mady, Abu yousf and his familly, Nizar and his son Rany, Mohammed Adous, Mohammed Almallah, Mustafah Wardah, Ali almagrabia, Samer, Ali almear, Ahamed Alkatieb, Mohammed Almasrea, salahedeen keshlaf , Radwan Ali Sead, Sadek Kamoka , Mohamed Arhuom, Dr. Abdalla Siddig, Mahmud Aref , Mohamed Nasim for their encouragement, advise and support during my stay in Germany.
    [Show full text]
  • Defoamers & Antifoams
    MUNICIPAL & INDUSTRIAL WASTEWATER TREATMENT Defoamers & Antifoams Effluent foaming or excessive foaming in a treatment process is not only a detriment to the discharge quality but also to treatment operations. Often, the application of a defoamer/anti- foam is all that is required to eliminate foaming issues. Foaming, often caused by excessive phosphorus, residual surfactants, or young/old biomass, are the most prevalent forms of foaming conditions seen in many treatment processes. Correctly addressing these foaming issues can rid the treatment process outfall of unsightly scum — improving the overall treatment process and ensuring that receiving stream quality standards are met. Coyne Environmental is uniquely positioned with the most comprehensive collection of treatment options available to assist the municipal and industrial water and wastewater treatment industries in meeting your specific treatment goals. www.coyneenvironmental.com MUNICIPAL & INDUSTRIAL WASTEWATER TREATMENT Defoamers & Antifoams Nocardia foaming is a tenacious, unsightly thick brown foam found in many biological processes which carries over into secondary clarifier and digester operations. Besides staining the surrounding surfaces, Nocardia reduces the transfer of oxygen in aeration onesz and hinders settling in the clarification stages leading to TSS carryover. It also infiltrates the digester operations reducing efficiencies and causes operational issues such as capacity limitations, overflowing, and gas production. Damage can also occur to various treat- ment processes due to entrained air. Reducing foaming due to Nocardia enhances treatment parameters but also benefits aesthetic and housekeeping issues allowing for a cleaner operation. Other wastewater treatment applications such as solids separation operations are also treated with defoamers. By dosing in drain lines from DAF’s, belt thickeners, and points of discharge from centrifuges, filtrate/centrate lines can be kept free of foam and flowing evenly without backups and overflows.
    [Show full text]
  • Select the Right Brown Stock Defoamer for Your Washing Operations
    Select the Right Brown Stock Defoamer for your Washing Operations Harold Petke, Senior Technical Adviser, Pulp ‐ Solenis LLC Michael Wang, Ph. D. Senior Application Manager, Solenis LLC Keywords: Brown stock washing (BSW), silicone defoamer, defoamer selection, washing aid, washing efficiency, operational cost reduction, silicone carryover, bleach chemical cost ABSTRACT: Brown Stock Washing is a critical step for optimizing production as well as controlling production costs. There are many different washing systems in use with a variety of configurations and characteristics influenced by fiber morphology, liquor parameters, etc., all with their own advantages and limitations. A common thread amongst all of the variations is that to operate beyond a very rudimentary level, they all use defoamer chemistry to function efficiently. With each process being unique in terms of configuration, equipment technology, capacity, process constraints, and control strategy, etc., how do you select the right defoamer for your washing operations? This paper reviews the selection criteria and methodology for determining the right product for any BSW system. The implications of product chemistry and characteristics are covered as well as the process characteristics and impacts of control strategies. By broadening the view beyond lab screening or what is being used at another location, selecting the optimal defoamer for a washer system is a comprehensive approach that rewards the operation with the best cost performance. INTRODUCTION: Pulp washing is crucial to the economics of chemical pulp manufacturing. The washing process separates fibers from the chemicals and dissolved wood components generated during the cooking process. Washed pulp quality is always weighed against production rate, bleaching costs, evaporator loading and make-up chemical costs.
    [Show full text]
  • Mec Defoamer Wb 500 Safe Water Based Defoamer
    MEC DEFOAMER WB 500 SAFE WATER BASED DEFOAMER EVIRONMENTELLY SAFE - NONPOLLUTING - NONFLAMMABLE - NONTOXIC - BIODEGRADABLE Provides excellent defoaming power in all applications including extreme acid’s and alkalizes. Controls all types of foam in sewage aerators, digesters, scum blankets, cooling towers, industrial cleaning operations, pulp and paper production, and other applications where foaming is a problem. DIRECTIONS: SEWAGE PLANTS: For long-term foam control in activated sludge plant, aeration tanks, digesters, sewage entry, or effluent lines. This low viscosity formulation that requires no pre-dilution to achieve complete and rapid foam control. Attach a small valve to the small bung of the defoamer drum and run a small tubing to the entry fume of the aeration tank or area where foaming of waste occurs. Drip 1 quart to 1 gallon of de-foamer per 10,000 gallons of waste (25-100ppm) to stop foaming and allow the aerators and digesters to function at maximum capacity and efficiency. For immediate foam relief, over spray the area with a diluted (1-10) of the anti-foam. INDUSTRIAL CLEANING & WASTE DEFOAMING: Spray or drip small amounts of de-foamer (100-200ppm) into the water-based system to control or eliminate foam. The defoamer does not affect paper processing, cleaning, cooling tower, or industrial processes. For quick foam knockdown, spray foam with a solution of the defoamer. FOR INDUSTRIAL USE ONLY CAUTION: Keep out of the reach of children. Mild eye irritant. Wash eyes with water until irritation stops. Prolonged contact can irritate the skin. Wash from skin with soap and water. Ingestion in quantity can cause severe diarrhea.
    [Show full text]
  • Defoamers for Paints and Coatings
    Defoamers for paints and coatings Selecting the best defoamer for a given formulation requires finding a balance between the defoaming power or strength of the defoamer and the compatibility and solubility of the defoamer in the system. Defoamers that are highly incompatible may give very effective foam control but may also cause surface defects, whereas more compatible defoamers may not give effective foam control. Increasing the defoamer use level can improve foam control but may also increase surface defects. The selection of a defoamer for a given formulation must take into consideration many factors, including the coating raw materials, method of manufacture, means of application, and cure conditions. Air Products offers a full spectrum of defoamer chemistries and formulations, including organic oil-based, mineral oil-based, siloxane-based and our own unique molecular defoamers based on Gemini technology. When selecting a defoamer, it is important to consider how all factors affect defoamer performance as well as the defoamer compatibility in a given formulation; therefore, defoamers must always be screened for suitability. The selector guide suggests the appropriate starting defoamers to screen, based on the formulation type and application method. Very suitable Point of Suitable addition Pigmentation Interior paints Exterior paints Coating Defoamer Defoamer type Grinding stage stage Letdown Pigmented Unpigmented Flat/satin Semigloss High-gloss Flat/satin Semigloss Gloss 2K epoxy 2K PU Acrylic Alkyd Polyester PU PU/acrylic acrylic
    [Show full text]